Does anyone else's DC go to bed after 8?

[Gateau]

My DS is 18 months old and does not go to bed until between 8 and 8.30. It's been this way for months.
We like him to eat with us - and it has evolved that way - and we don't eat until about 6.30 when DH gets home. Then he has a short play/watches TV before having his milk and going to bed.
Most other people seem to get their DC into bed for 7 - for me, this is impossible!
Does anyone have similiar experiences to me?

Dd goes 8-8.30 and has since she was about 1. Most of our friends' dcs go to bed about the same with a few going 7ish and one or two much later.